Hi there! Which CPU and motherboard are you running? I have the flickering problem on a 2600k/p67 chipset board. but it looks like users with haswell don't have this problem.
For what it's worth, I'm running twin 780 GTXs in SLI and don't notice any major latency issues, it's buttery smooth with almost everything turned on (not running DSR however, that's been giving me serious flicker issues any time I try to use it).